ABSTRACT
A recently developed Latex agglutination method known as "KATEX" for detecting leishmanial antigen in urine of Kala-azar patients was evaluated on 97 Kala-azar cases and 35 controls in the department of Microbiology, Mymensingh Medical College during the period from March' 2004 to February' 2005. The method yielded sensitivity as 100% and 82.8% in 33 confirmed and 64 ICT positive cases respectively. Since 8.6% controls showed antigen positive results, so specificity of KATEX was calculated as 91.4%. KATEX methods for antigen detection in urine should be used as an early immuno-diagnostic test as it has yielded high sensitivity. But interpretation of a positive test must be made cautiously having correlation with clinical findings as because it becomes false positive in Kala-azar free person. Further elucidation of KATEX method including larger population from community giving particular emphasis on its prognostic use was strongly recommended.
Subject(s)
Adolescent , Adult , Animals , Antigens, Protozoan/urine , Bangladesh , Child , Child, Preschool , Female , Humans , Latex Fixation Tests/methods , Leishmania donovani/immunology , Leishmaniasis, Visceral/diagnosis , Male , Middle Aged , Sensitivity and SpecificityABSTRACT
A latex agglutination test to detect urinary antigens for visceral leishmaniasis [VL] was studied. In 204 patients with suspected VL, KAtex had a sensitivity of 95.2% with good agreement with microscopy smears but poor agreement with 4 different serology tests. It was also positive in 2 confirmed VL cases co-infected with HIV. In all KAtex-positive confirmed cases actively followed up after treatment, the test became negative 1 month after completion of treatment. While KAtex had a specificity of 100% in healthy endemic and non-endemic controls, the direct agglutination test [DAT] was positive in 14% of the KAtex-negative healthy endemic controls. KAtex is a simple addition to the diagnostics of VL particularly at field level and as a complementary test for the diagnosis of VL in smear-negative cases with positive DAT results
Subject(s)
Humans , Antigens, Protozoan/urine , Case-Control Studies , Child, Preschool , Endemic Diseases/statistics & numerical data , Enzyme-Linked Immunosorbent Assay/standards , Fluorescent Antibody Technique, Indirect/standards , Immunoblotting/standards , Latex Fixation Tests/methods , Leishmania donovani/immunology , Parasitology/standardsABSTRACT
A simple and rapid staphylococcal coagglutination test for the detection of Toxoplasma gondii antigens in mice urine is described. A suspension of protein-A containing Staphylococcus aureus coated with rabbit hyperimmune serum was used as reagent. The sensitivity of the antigen assay was found to be at least 118 ng of the antigen protein per ml. No coagglutination was observed when the reagent was challenged against antigenic solutions of other parasites. The suitability of the method for detecting antigens of T. gondii in urine samples was studied by experimental toxoplasma infection in mice. Before the staphylococcal test, the urine samples were double serially diluted in 0.1 M PBS. From the second day on all samples from infected mice were positive at 1/16 dilution. At this dilution, all samples from non infected mice were negative or did not produce coagglutination. This method might be used in the rapid etiological diagnosis also in human cases of acute toxoplasmosis